In animals with NEC, there was increased staining in the crypts near the apical membrane compared with control animals, BIF treatment normalized claudin-3 expression similar to control animals and redistributed of claudin-3 to the apical and basolateral membranes along the crypt-villus axis; ZO-1was mainly localized in the cell boundaries and in the cytoplasm along the crypt-villus axis in all groups with the least signal detected in the NEC group, whereas treatment with BIF significantly increased ileal ZO-1 expression to similar levels seen in control animals. The gene discussed is CLDN3; the disease is necrotizing enterocolitis.